High speed switches are more and more needed in sophisticated telecommunication networks. However an important problem resides in the fact that huge investments which were already made should be preserved as much as possible. Therefore, it is desirable that high speed switching systems of the future will still allow attachment to the existing communication links.
Another serious problem comes from the different physical locations of the attachment lines forming the network topology of a given industrial area. Indeed, it very often appears that line adapters are to be located or distributed at different physical areas of an industrial site. This strongly enhances the difficulties of connections of the different elements to the centralized switch core.
At last, the switching system should permit wide multicasting capacity (i.e., the capability of duplicating the data cells at different destinations), and achieve the attachment to Asynchronous Transfer Mode (A.T.M.) lines.